Commit fb7e1600 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

fs: add an iopoll method to struct file_operations 



This new methods is used to explicitly poll for I/O completion for an
iocb.  It must be called for any iocb submitted asynchronously (that
is with a non-null ki_complete) which has the IOCB_HIPRI flag set.

The method is assisted by a new ki_cookie field in struct iocb to store
the polling cookie.

Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Reviewed-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 758a58d0

Documentation/filesystems/vfs.txt

+3 −0
Original line number Diff line number Diff line
@@ -857,6 +857,7 @@ struct file_operations { 
	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);

	ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);

	ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);

	int (*iopoll)(struct kiocb *kiocb, bool spin);

	int (*iterate) (struct file *, struct dir_context *);

	int (*iterate_shared) (struct file *, struct dir_context *);

	__poll_t (*poll) (struct file *, struct poll_table_struct *);
@@ -902,6 +903,8 @@ otherwise noted. 


  write_iter: possibly asynchronous write with iov_iter as source



  iopoll: called when aio wants to poll for completions on HIPRI iocbs



  iterate: called when the VFS needs to read the directory contents



  iterate_shared: called when the VFS needs to read the directory contents

include/linux/fs.h

+2 −0
Original line number Diff line number Diff line
@@ -310,6 +310,7 @@ struct kiocb { 
	int			ki_flags;

	u16			ki_hint;

	u16			ki_ioprio; /* See linux/ioprio.h */

	unsigned int		ki_cookie; /* for ->iopoll */

} __randomize_layout;



static inline bool is_sync_kiocb(struct kiocb *kiocb)
@@ -1787,6 +1788,7 @@ struct file_operations { 
	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);

	ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);

	ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);

	int (*iopoll)(struct kiocb *kiocb, bool spin);

	int (*iterate) (struct file *, struct dir_context *);

	int (*iterate_shared) (struct file *, struct dir_context *);

	__poll_t (*poll) (struct file *, struct poll_table_struct *);

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